The proposed research will apply Logan's instance theory of automaticity to the process of perceptual learning and the resulting transient stimulus-repetition effects. The theory purposes that episodic memory for a task consists of representations of the stimulus characteristics and the required response. The theory posits that with practice, the processing becomes efficient, not because of improvements in the standard procedure for doing the task, but rather because of a high probability of being able to trigger responses based on retrieve memory traces for similar episodes. The theory has previously been tested only on semantic tasks. The proposed research will test its ability to account for learning effects in a perceptual task: visual search. The proposed research will also begin to address the changes necessary in order for the theory to account for the transient influence of stimulus-repetition on processing. Understanding how episodic memory influences skill learning will help clinicians plan training for people with memory impairments. Understanding how perceptual learning relates to semantics learning will advance understanding of how perceptual skills can be influenced by training.